Centrifugal fan
A centrifugal fan is a mechanical device for moving air or other gases in a direction perpendicular to the axis of rotation of the fan. Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink; such a fan is also called a blower, blower fan, turbo fan or squirrel-cage fan (because it resembles a hamster wheel).